426 LECTURE XV. 



on the monuments of Latopolis^ Ombos, or Apollonipolis 

 Magna, liave detaclied themselves from the walls and descended 

 into the plains." 



The same constancy of characters can be traced in the other 

 races with which the Egyptians came in contact. The Jews 

 are as easily recognisable as the Tatars and Scythians with 

 whom Eameses III was at war. In the same way we observe 

 npon the Assyrian and Indian monuments the characters of 

 such races as still inhabit these regions, so that the constancy 

 of race characters is everywhere rendered evident. But the 

 example of Egypt teaches also that slight changes of climate, 

 as well as limited intermixture, have an insignificant influence 

 on the character of a race. For more than four thousand 

 years have Negroes, Berbers, and Egyptians inhabited the same 

 Nile valley, and propagated there without any essential change 

 in their characters. At a later period there was an immigration 

 of Greeks, Persians, Arabs, and Turks, still without changing 

 the original stock. These conquerors added but a small per- 

 centage to the existing population, and stood to it nearly in 

 the same relation as limited intermixture, which, by recrossing 

 with the parent stock, is absorbed in it, or leaves only a slight 

 residue. 



Whilst thus the constancy of the natural races of mankind 

 is established beyond any doubt, we must, on the other hand, 

 not forget that most of them possess a certain flexibility, and 

 show, when transplanted into difierent media, certain changes 

 which are the result of their adaptation to new conditions. As 

 it is upon this point that the advocates for the unity of the 

 human species base their arguments, we are compelled to 

 scrutinise the respective facts. 



Let us, at the outset, remember that many races, though 

 they remain on the same spot, are apt to undergo certain 

 changes, the result of progressive civilisation. It is chiefly 

 the height of the skull, and the development of the frontal 

 region, which is thereby afiected, by which the internal capa- 

 city of the cranium, and the cerebral mass itself are increased. 

 We have already pointed out, that in races capable of civilisa- 

 tion, the anterior sutures remain open longei', and are ob- 



